There are many transport applications wherein transported merchandise is housed in a single or several layers so as to prevent damage thereto, multi layered in cages, coops or containers carried by a large transport vehicle bed, such as a flatbed trailer truck. Unloading of the containers in a systematic manner so as to avoid piling or congestion of the contents in the unloading area, or so as to avoid damage to the contents has long been a problem to the transport industry and to the various unique industries processing the contents. The transport of fruit and vegetables that cannot tolerate direct multi-level packing, and of live animals that must be housed in cages or coops containing only several of such animals, are but several examples of such industries to which the present invention applies.
One unique example, and that to which the preferred embodiment of the invention will be directed, is the poultry processing industry. The reader will understand that while the invention will hereafter be described with respect to the handling and processing of poultry, the principles of the invention are not to be limited thereby.
Live poultry is generally transported to modern processing plants on large flatbed truck trailers carrying the poultry in multilayer cages or coops. A transport truck typically carries as many as 160 coops for chickens, holding approximately 13,200 chickens, and as many as 120 coops for turkeys, holding approximately 1,440 turkeys. The poultry cages or coops are normally multi-level, usually 6 levels high for turkeys and up to 12 levels high for chickens.
Those used for transporting turkeys are normally mounted on both sides of the truck trailer with their coop doors or gates facing the outside of the trailer. The multi-level cages are generally 8 to 10 feet high, are built in sections of 8 to 16 feet long and are generally about 45" in depth, thus allowing a 6-inch ventilation air space between the coops down the middle of the truck. The doors of turkey coops generally lift up and slide back into the coop at their tops, in overhead door manner.
In the chicken broiler industry, a wider variety of transport coops are used. The most common multilayer coop is 6 levels high, measuring 8 feet long, 4 feet wide and 52 inches high. The coops are generally divided on each level into three sections. The doors of the chicken coops generally are hinged at the bottom of the coop and pivot outwardly. Some coops do not use doors or gates, but are built in drawer fashion. Since chickens have a flightier temperament than turkeys, loading and handling of chickens is often performed at night; whereas turkeys can be handled at anytime of the day.
Most modern poultry processing facilities use a conveyor system to transport the carcasses of the birds from one work station to the next during the processing operations. Typically, a conveyor system is used in the processing plant which includes an endless conveyor chain mounted on an overhead track assembly. A succession of shackles are attached to and hang downward from the chain, each shackle being adapted to receive and hold the legs of an individual bird in inverted or head-down configuration. The shackled bird typically moves some distance into a slaughter area where it is stunned by an electric shock, or is anesthetized before its neck is cut by a revolving knife. Proper bleeding of the bird is facilitated if its heart is still beating, which generally dictates that the bird not be stunned or anesthetized until just prior to reaching the slaughter area.
Unloading of poultry from their carrying cages or coops of the transport vehicle into the restraining shackles has long been a problem for the processing industry. Such unloading has been very labor intensive, is difficult and often dangerous to the person doing the unloading, is traumatic to the bird being handled, and often results in injury or damage to the bird.
Due to the large size of turkeys, their unloading has generally been done by hand, wherein an unloading person opens one coop at a time and individually removes each turkey from its transport cage and lifts and places the bird into its confining shackles. Since turkeys generally weigh between 25 and 40 pounds, the unloading task is extremely strenuous, time consuming and difficult and the turkeys are generally uncooperative in the process. The process also results in damage to the bird as it moves in inverted position along the shackle conveyor. The bird's struggle to free itself from the shackles can cause severe stress often resulting in body bruising and broken bones and lowering the grade of the meat.
Direct placement of turkeys from the transport container into an inverted leg shackle position gives rise to other potential problems during the processing stage. The birds will generally not defecate while in transport or while in an inverted shackled position. Therefore, when birds are unloaded in the conventional manner, it is common for their large intestines to be full. When a cut is made around the bird's vent area during processing, any cut into the large intestine will enable fecal matter from the large intestine to leak out onto the bird's skin. The contaminated area must be cut away, causing downgrading of the carcass. Such contamination could be significantly reduced, if the birds had a chance to defecate in a standing position after unloading from the coops and before being placed into leg shackles.
Generally, the turkey unloading operation is very labor intensive, requiring a number of workers to perform the unloading process, which is typically simultaneously performed from both sides of the transport truck. The shackle-containing conveyors are generally placed along each side of the truck, and the unloading workers open one cage at a time and individually remove and hang each turkey into its restraining shackles. Typically the unloading personnel stand on platforms on either side of the transport truck. The platforms are raised and lowered to place the unloaders at the most convenient elevation for unloading the turkeys from the various coop levels. While attempts have been made to automate and simplify the shackling process (see, for example, U.S. Pat. No. 5,108,345), the basic manual process of unloading turkeys from the transport coops has not changed.
Methods have been devised to transport poultry, and in particular chickens, to a processing plant in individual support containers or restraints (as, for example, illustrated in U.S. Pat. Nos. 3,260,239 or 3,234,915 or 4,215,654). Such transport apparatus is fairly costly and still requires manual labor to individually secure the chickens within such restraints or containers prior to transport. Accordingly, the vast majority of the industry still transports chickens to the processing plant in cages or coops containing a plurality of chickens that are generally unrestrained for movement within the cages during transport.
While the basic technique of unloading turkeys at the processing plant has not changed much over the years, a number of techniques have been used in the art for unloading chickens from their transport coops. The greater flexibility in handling chickens is due in part to their smaller size and lesser susceptibility to injury as compared to the larger turkeys. One unloading technique has employed permanently mounted multilayer coops on the transport truck, with side opening doors. Chickens are individually unloaded from the coops through the side doors, in the same manner previously described for turkeys, or are pulled out onto conveyor belts that are aligned with the doors, for transport by the conveyors in the processing plant. The chickens are then individually placed into shackles in manner similar to that described for turkey processing operations. Another type of chicken transport coop is configured in the nature of a drawer, which is slid out or opened at the processing plant, and the chickens are individually lifted from the drawer.
Other unloading techniques require removal of one or a stack of coops from the transport vehicle before the chickens are emptied from the coops. In general, such techniques are labor intensive and time consuming and require a forklift vehicle to lift the coop modules from the transport vehicle to the unloading station and back again. One such technique takes the removed module of coops and tips the entire module toward its opened door side, dumping the chickens out of the coops and onto a wide conveyor belt in the processing facility. With this technique, as many as 720 chickens are dumped onto the 4 foot wide conveyor belt at a time. Chickens from the upper coops fall a considerable distance onto the belt and/or onto other chickens, often causing injury or bruising of their meat. A variation of this technique moves the entire multilayered coop module to an unloading station that aligns a plurality of multi-level chutes or slides with each coop level. The entire coop module is then tipped toward the chutes, causing the chickens to be dumped out of their cages and guided by the chutes onto a large collection conveyor. Since multiple levels of chickens are simultaneously deposited on the same delivery conveyor belt, such technique can result in undesirable injury to the chickens due to bumping each other in the congested collection areas and due to the upper layer chickens falling onto chickens already deposited on the belt from lower levels.
Accordingly, while many techniques have been used in the art for unloading poultry at a processing plant from transport containers or coops, each suffers one or more drawbacks of: inflicting damage to the birds, being labor intensive, exposing the unloading personnel to danger from the birds and to injury due to excess lifting, and/or complication or cost of implementation. The present invention addresses the above problems and shortcomings of prior art unloading apparatus and techniques, and provides an efficient and cost effective method and apparatus for unloading poultry in a manner that minimizes damage and stress to the birds and which requires little labor and isolates the unloading personnel from undesirable contact with the birds being unloaded.